1. Field of the Invention
The disclosed embodiments relate generally to the field of aeronautics. More specifically, the invention relates to the technologies of propeller manufacture and design.
2. Description of the Related Art
Propellers transmit power by converting rotational motion into thrust. This thrust is used to propel a vehicle, e.g., an aircraft, ship, or submarine through a fluid. Some propellers have a fixed pitch—in other words, the angle of the blades do not change as the aircraft is in operation. Other propellers blades change angle to accommodate different operating speeds of the aircraft. These are known as variable-pitch blades.
One conventional design for a fixed-pitch propeller is made of solid, single piece of Aluminum. For this kind of blade, the entire apparatus is produced as an integral piece of material. Another fixed-pitch design is constructed of a single piece of laminated wood which is bolted onto the rotation drive on the plane. With the wooden version, the propeller is generally secured using a crush plate. The crush plate is bolted against the hub portion of the propeller to distribute loads created by the attachment bolts. Yet another conventional single-piece propeller is comprised of composite materials. This design uses a wet lay-up process using solid carbon fiber cores. The solid carbon fiber cores are relatively heavy, but are necessary to carry the structural loads during propeller operation, because the composites skins alone are incapable of doing so. Other propeller designs use separate propeller blades which are retained by more complex retention mechanisms.